This invention relates to an injection apparatus in the form of a syringe which may be delivered as a projectile for contact with an animal and, more particularly, to an animal identification and medication syringe for marking, monitoring, and medication of domestic animals and wild life.
A number of devices exist for injecting medication into animals and for marking and monitoring animals. Some of these devices treat animals by means of pole-mounted syringes or syringe-bearing projectiles that enable the user to medicate the animal from a safe distance. In addition to disposable or single use delivery systems, there are also devices which enable the delivery systems to be retrieved from the animal for reuse. For example, for those syringes which are shot through a gun for delivery of the medication, string retrieval systems are available which enable the user to retrieve the syringe by the connected string/line.
There are a number of disadvantages to pole-mounted syringes or other systems which require the user to come close enough to the animal to contact the animal with the syringe. That is, even with the pole-mounted syringe, the user is at close quarters with the animal which can endanger the user. Many of the syringe-bearing missile systems utilizing string retrieval are difficult to retrieve as such strings may become entangled with the animal itself or surrounding objects.
One example of a syringe which is delivered as a projectile for medicating an animal is U.S. Pat. No. 5,437,641. This invention also discloses a means by which the syringe is ejected from the animal once medication is delivered to the animal.
Another example of a projectile type syringe includes U.S. Pat. No. 3,715,990. This invention discloses a dart projectile with a cylinder mechanism for discharging medication upon impact. Within the cylinder is a plunger piston enclosing an explosive charge. Impact fires the explosive charge, thereby moving the plunger piston and causing the medication to pass through the syringe into the animal.
Although the foregoing inventions may be adequate for their intended purposes, a tremendous need still exists in domestic and wild life animal medicine for a syringe that can be shot through the air to deliver large or small volumes of medication to a distant target with pinpoint accuracy while simultaneously marking the target animal for future identification. A further need exists for this syringe to be lightweight, durable, compact, reusable, easily disinfected, and capable of penetrating both thick and thin hides with ease. Additionally, it is desirable that the impact of the syringe against the animal cause minimal tissue damage, and that the syringe be easily manipulated to allow one or more different types of medication to be delivered simultaneously, along with selected quantities of each of the medications.
The invention disclosed below meets each of these needs, as fully explained in connection with the below description of the invention and the accompanying drawings.
In accordance with the present invention, an animal identification and medication syringe is provided. In its simplest form, the syringe includes a barrel, a plunger piston which moves longitudinally within the barrel in response to air pressure within the barrel, and a syringe needle for penetrating the hide of an animal and for introducing medication into the animal. The distal end of the barrel includes a valve mechanism or needle plug assembly which enables the plug assembly to either prevent the flow of medication through the needle, or to allow flow of medication through the needle depending upon the position of the barrel with respect to the needle. The plunger piston separates the interior opening of the barrel into an air pressure chamber, and a medication chamber. In use, the medication chamber is filled with a desired quantity and type of medication. Air pressure is then introduced into the air pressure chamber thus forcing the plunger piston against the medication within the medication chamber. The needle is positioned initially so that the needle plug assembly prevents flow of medication through the needle. Once the device impacts the animal, the syringe is moved forward or distally which allows medication to flow through the needle into the animal. The air pressure within the air pressure chamber forces the plunger piston in the distal or forward direction thus evacuating or emptying the contents of the medication chamber through the syringe needle into the animal. Means are provided in the form of a pressure reacting member for forcing the needle in a proximal or rearward direction once the medication chamber is emptied through the needle. Thus, once the plunger piston moves to its most forward or distal position emptying the medication chamber, the needle is then forced in the proximal direction causing the needle to be ejected from the hide of the animal.
The preferred embodiment of this invention may include one or more needles. The needle plug assembly may be adapted for preferably one to three needles. One advantage of multiple needles is reduced trauma to the animal because the size of each of the multiple needles may be smaller, thus avoiding a relatively large and invasive puncture made by a single larger diameter needle. Additionally, use of multiple needles provides greater gripping capability in terms of the syringe remaining attached to the animal while medication is delivered. Also, a multiple needle device can allow the separate injection of different medications simultaneously with the same impact to the animal. As well understood, the physical mixing of medications prior to actual delivery to the animal is most oftentimes undesirable.
In the preferred embodiment, the specific structure of the invention includes a hollow cylindrical barrel with a proximal barrel plug at the proximal end of the barrel, and the needle plug assembly positioned at the opposite or distal end of the barrel. The plunger piston is slidable within the hollow opening of the barrel in response to air pressure which is introduced into the barrel through proximal barrel plug. The needle plug assembly acts as a valve which determines whether medication can flow through one or more needles which are secured within the needle plug assembly. Each of the needles used with the device of this invention includes a proximal opening, a distal opening, and a central passageway extending between the proximal and distal openings. Prior to the syringe being delivered to the animal, each needle is placed such that the proximal needle openings are covered by the needle plug assembly. Once the medication chamber has been filled, and the plunger piston is pressing against the medication chamber due to air pressure within the air pressure chamber, the syringe can be delivered as a projectile to the animal. As the needle(s) enter the hide of the animal, the forward or distal movement of the barrel causes the needle plug assembly to slide forward over the needle(s) uncovering the proximal needle openings, thus allowing the medication to flow through the proximal needle openings, through the central passageways, and out the distal needle openings into the tissue of the animal. A needle disk shaft which is positioned in the medication chamber and which extends in the proximal direction is contacted with the plunger piston as the plunger piston moves forward or distally to evacuate the medication chamber. A needle disk which is rigidly connected to the distal end of the needle disk shaft is pressed against the hide of the animal upon impact. The syringe is forced away from the animal once the plunger piston moves to its most distal position, causing the needle(s) to be removed from the animal. The needle disk shaft and needle disk may comprise the pressure reacting member. Although a needle disk can be used, it shall be understood that the needle disk can simply be the distal end of the needle disk shaft, the distal end being large enough so as not to penetrate the hide of the animal.
A marking/disinfecting disk is mounted over the needle disk adjacent the distal tips of the needle(s). As the barrel moves forward upon impact with the animal, the marking/disinfecting disk swipes the portions of the needle(s) which eventually penetrate the hide of the animal. This contact allows the needles to be disinfected by contact with the disinfecting/marking disk which may be dipped or soaked with a disinfectant solution. Additionally, the marking/disinfecting disk can be soaked in a dye solution which enables the animal to be easily marked or tagged upon impact by the syringe.
Various types of needle tips can be used. One particularly advantageous needle tip arrangement includes a trochar point. The trochar point tip comprises a triangular point consisting of three flat cutting surfaces. This trochar point allows a needle to cut through even the toughest, thickest hides with much less force than conventional needles. As the needle penetrates deeper into the hide of the animal, the diameter of the needle increases thereby wedging itself into the small hole originally cut by the small trochar tip. Thus, the needle is better retained within the animal, and a minimal amount of medication is lost after ejection of the needle away from the animal.
A swedge or enlarged portion on the needle disk shaft causes a slight spread of the needles once they have penetrated the animal. This feature further ensures that the syringe needles stay within the animal during medication delivery.
Also provided herein is a rapid refill syringe mechanism. This refill mechanism enables syringes to be rapidly refilled with a desired medication. The refill mechanism is similar to the syringe of this invention in that the refill mechanism also includes a barrel, and a piston which separates the barrel into an air pressure chamber and a medication chamber. A plug is provided at the proximal end of the refill mechanism which allows air to be introduced into the air chamber. Medication fills the medication chamber. In order to refill a syringe, a needle of the syringe is inserted into a needle plug insert, and the fluid within the medication chamber is then forced through the syringe needle into the medication chamber of the syringe. The filling mechanism may have a plurality of needle plug inserts adapted to receive single or multiple syringe needle arrangements.
Additional advantages will become apparent from the description which follows, taken in conjunction with the accompanying drawings.